by Michelle Healy, USA TODAY

by Michelle Healy, USA TODAY

Family squabbles are to be expected, especially during times of holiday togetherness. But a new study suggests that seemingly simple conflicts between adolescent siblings can have negative consequences for teens' later emotional well-being.

Researchers report that conflicts about personal space and property, such as borrowing items without asking and hanging around when older siblings have friends over, are associated with increased anxiety and lower self-esteem in teens a year later. And fights over issues of fairness and equality, such as whose turn it is to do chores, are associated with later depression in teens.

Not all sibling conflicts are equal, and not all "influence adolescent adjustment in the same way," says Nicole Campione-Barr, an assistant professor of psychological sciences at the University of Missouri and lead author of the study, published today in the journal Child Development.

"Previous research has examined the impact of frequency and intensity of conflicts between siblings, but not how different types of conflict might impact individual adjustment," she says.

Using interviews and questionnaires, Campione-Barr and colleagues had 145 pairs of siblings (average ages 15 and 12) rate different topics of possible conflict with their sibling, noting the frequency and intensity of the arguments.

When researchers examined correlations between the arguments and teens' self-reports of depressed mood, anxiety and self-esteem after one year, topics related to fairness and equality and invasion of personal domain were most common.

"Fights about borrowing things without asking, going into my room without asking, and other issues about privacy invasion, such as being around when my friends are over, are particularly important for adolescents because this is a time in their lives when they're striving for independence and autonomy from the family," says Campione-Barr.

Feeling as though someone's always looking over your shoulder or constantly tagging along and never giving you personal space "is going to make you anxious and nervous and concerned about whether you're your own person and whether you'll ever get to do your own thing," she says. "And it will have a similar impact on self-esteem as well."

Conflicts associated with fairness are mostly about "shared resources and responsibilities within the family," she adds. "If there are a lot of these conflicts, and if they are particularly frequent, it's more likely an indication that one sibling is not getting a fair share of the family pie. They're the ones that are being pushed out and are the less powerful of the two. This is why we think it's particularly problematic for depressive symptoms."

Results related to depression were found in all adolescents, regardless of age or sex, but results related to anxiety and self-esteem appeared to be more common for some siblings than others -- younger brothers with older brothers and girls with brothers had more anxiety; teens in mixed-gender sibling pairs had lower self-esteem.

Prior research has shown that sibling conflict has negative implications for youth adjustment, but this new study, "contributes significantly in showing that what teens fight about makes a difference," says Susan McHale, director of the Social Science Research Institute at Penn State University.

And the findings about the significance of equality and fairness add to research on parents' differential treatment of siblings, which is known to have "negative implications for youth adjustment," McHale says. The new study documents "how these dynamics cross over to affect sibling relationships, and through those, youth depression." â??

Although parents may be inclined to intercede and negotiate these arguments, "some research has shown that by adolescence, when parents step in too much, it makes the relationship worse and makes conflict worse between adolescent siblings," says Campione-Barr.

Better alternatives for preventing disputes and avoiding favoritism include setting household rules, such as knocking before entering a sibling's room, she says. Also, sticking to a calendar for chores and setting defined time limits for turns with household electronics and other shared devices can help reduce conflicts.